Means for compressing printing plates



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Patented Aug li, 1925 istat LESLIE W. CLAYBOURN, 0F MILWAUKEE, WISCONSIN.

MEANS FOR COMPRESSING PRINTING PLATES.

Original application filed March 19, 1921, Seria] No. 453,665. Divided Aand this application filed December 7, 1922. Serial No. 605,455.

To all whom t maz/ concern.'

Be it known that I, LESLIE W. CLAYBOURN, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain -new and useful Improvements in Means for Compressing Printing Plates, of which the following is` a specification.

My present application is a division of an application heretofore filed by me in the United States Patent Oflice March 19, 1921, as Serial N o. -453,665, for method of correcting .printing plates and printing plates produced thereby. Y

I do not herein claim the-method of correcting printing plates, or the method of compressing printing plates, or the printing plates produced thereby, herein shown and described, having shown, described and claimed the same in my aforesaid prior application, Serial No. 453,665. v

It is the object of my invention to provide new and improved means whereby to minimize or substantially reduce so-called makeready on the printing press, and I have shown my invention applicable to flat printing plates and also to curved printing plates, although portions of my invention are especially employable in connection with curved printing plates.

It is the object of my invention to provide novel means whereby to bring all portions of the printing surface into the projection of the saine surface, that is, into the same plane if the plate be a flat plate, and into the same surface of the sector of a cylinder if the plate be a curved plate; further, to provide new and improved means whereby to compress the backing of a printing plate in order to impart to thesame a greater density than when the plate is first formed; further, to provide means whereby to compress a printing plate for correction of itsI printing surface with pressure per area of surface greater than the printing pressure per area of surface applied to the plate; further, tov

provide means `whereby to cause differential compression of the backing of the printing plateaccording to the solidities of the various portions of the printing surface of,the

printing plate; further, to provide means for compressing the backing of a print-ingplate with greater density at its solid printing portions than at its high light or light printing portions; further, to provide new and improved means to correct a printing plate by pressing those portions thereof whichl print with too light an impression toward the printing Surface of the printing plate; further, to provide new and improved means whereby to compress the backing of the printing plate while confining said backing as a whole in the plane of said plate; further, to provide new and improved means whereby to compress the backing of a printing plate while maintaining the prlnting lines in their original printing distance re-` lations in the printing surface and to avoid stretching of its'printing surface; further,

to provide new and improved means for pressing the sunken or concave print-ing portions of the printing surface of the printing plate located between printing edges into the plane of said printing edges.

I have found that, when printing plates as heretofore made, the printing surface of the plate will let down or the backing thereof compress in uneven manner away from the proper printing surface to cause'imperfeet printing. It is a further object of my invention, therefore, to provide means whereby to'compress the printing plate and especially the backing material thereof to a density at least as great as any density which might be imparted t'o the printing 85 plate or its backing byv printing pressures, especially at the solid portions of the printing areas.

The invention will be .further readily understood from the following description and claims, and from the drawings, in which latter:

Fig. 1 represents a plan View1 of an exemplifying printing plate.

Fig. 2 is a` cross-section of the same taken 95 on the line 2-2 of Fig. 1.

Fig. 3 represents a cross-section of a portion of the printing plate shown in Fig. 1 taken on the line 3-3 of Fig. 1, to illustrate the usual relations ,between the printing sur- 10o face and the backing surface in their crude state, as in present methods, the plate being shown enlarged to disclose imperfections inherent in such plates.

i Fig. 4 is a cross-sectional view ofthe same plate, taken on the same section line as in Fig; 3, the plate being sho-Wn subjected to compression by means of an exemplifying compressing member, for compressing the printing plate.

Fig. 5 is a front elevation of an exemplifying machine, partly broken away, for compressing the printing plate'.

Fig. 6 is a plan vieW of one corner of the compressing member, which is exemplified as a compressing member for printing plates having a preponderance of intermediate solidities of printing surface.

Fig. 7 is a plan vieW of a portion of an exemplifying compressing member for printing plates having a preponderance of solid printing portions.

Fig. 8 is a cross-section of the same, on the line 8-8 of Fim 7.

Fig. 9 is a plan view of a similar compressing member for printing plates heling' a preponderance of high-lights in the print-- ing surfacethereof. d

Fig. 10 is aA cross-section of the same, taken on the line 10-10 of Fig. 9.

Fig. 11 is a plan view of a portion'of an exemplifying compressing member having connected pressing faces.

Fig. 12 is a cross-section ofthe same, taken on the line 12-12 of Fig. 11.

Fig. 13 is a plan view of the compressed backing of the printing plate illustrated in Fig. 1l, partly broken away.

Fig. 14 is a front elevation illustrating an exemplifying machine for compressing a curved printing plate.

Fig. 15 is a side elevation of the same.

Fig. 16 is a vertical cross-section of theA same, taken on `the line 16-16 of Fig. 15, illustrating the exemplifying means for compressing a curved printing plate.

Fig. 17 is a vertical axial section of the same, taken on` the line 17-17 of Fig. 14, partly broken away.

Fig. 18 is a vertical section of a detail of the same, taken on the `line 18--18 of Fig. 17. 1

Fig. 19 is a perspective view of a detail of the same; and,

Fig. 2O is an enlarged view of a sector of ai compressing member fer compressing a curved plate, taken on the line 16-16 of Fig. 15. l

It has heretofore been a usual practice in making ready for the printing from printing plates, to overlay the tympan of the printing press on which the plates are to be printed at those portions at which the printing appears too light in the proofs, or to underlay the printing plate at such portions, or to both overlay and underlay at the insufficiently printing portions, and to cut taken the tympan Where the printing appears too heavy, with the result that uneven surfaces are obtained both. inthe tympan and at the bottom of the printing plate, such system.

plate, this system also producing unevein ness of printing surface.

These uneven, Waving or undulating suifaces at the rear face of the printing plate, or at the face of the tympan, or both, also, in the courseof printing, or during a long run-,vary from their original states, especially under the heavy print-'pressures necessary to be employed under such old methods,

resulting in differences in appearance ofthe printing during different portions of the run and making subsequent make-readies necessary.

ll avoid all these objections by' providing means whereby all portions of the printing surface and the printing lines and areas throughout the printing plate are brought into the same projection of a given surface, determined by printing pressure,thatis, into the same plane if the Jlate be a flat plate and into the same sur ace of the seetor of a cylinder if the plate be a curved plate.

I am thereby enabled to produce superior printing, and also to print with a tympan Whose impress surface is throughout substantially the projection of the same surface, so that successive printings by different plates or printing elements may be received by the same portions of the tympan, Whereby my invention is especially adaptable for preparing printing plates for so-called u'et printing, in which successive printings in different colors are printed upon the same sheet, during its single passage through the printing press, as Well -as to all other chai'- acters of printing, enhancing the appearance' and beauty of the printing and enabling me. to reproduce the appearance of solids, high-lights and intermediate printing effects, in highly contrasted relations in the printing from co-ordinated plates repre-` senting different colors, and avoiding the humps and hollows in the make-ready for one color which are detrimental to the makeready for another color in the old methods mentioned, and enhancing true registry of the printing lines.

The term projection of the same surface, and corresponding expressions throughout the description yand claims, are to be understood as meaning the plane of a flat surface, as applied to a` plane surface,

aaaaiae and the same. curved surface of the sector of a cylinder or cylindrical surface, as applied to a curved surface. The term is employed for convenience,` and avoids confusion in expression Where itis desired to describe or claim both or either characters of surface.

Employment of my improved device further enables printing to be accomplished With considerably lighter printing pressures and with harder tympans than under such older methods now in general use and materially increases the numbers of imprints Which can be obtained from one make-ready of the printing subject, and by mea-ns of my invention, further, the solid portions ofthe printing plate are compressed to greater extent than Jhe high-lightportions of the plate, the density of compression being graduated by or dependent on the comparative solidities of .the various printing portions of the printing plate, and printing plates are produced which retain their clarity of printing effect throughout long periods of use.

The projections, that is, the planes or sectors which the printing surfaces or printing 1 lines are caused to occupy by employment of my invention, are intended to be measured by print pressures, as they are ordinarily too refined for observation by the naked eye.

A printing plate' is exemplified at 21, and inthe present exempliication comprises a printing shell 22, which may be of usual electro-deposited metal, for instance, copper deposited on the matrix in'electro-plating,

Aand a backing 23 on Which the printing shell is xedly supported, usually cast into the shell. `This backing is usually a composition composed for example of lead, tin and antimony, in the proportion, for example, of ninety pounds of lead and five pounds each of tin and antimony. It is obvious,

however, that other backing material may be employed and that my invent-ion is not limited to means for operating on printing lplates thus formed. The printing plate 21 is shown-as a flat plate. The printing plate operated on may be a curved plate, as shown at 24. The curved plate is in construction the same as the flat plate, and may comprise a printing shell 22 and a backing 23.

lVhen employing my improved device, the printing plate may at its margins be provided With bearers25, which may if desired be separated from the printing surface by grooves 26, and the printing plate may also have intermediateI or interior bearers, exemplified at 27. The marginal bearers and intermediate bearers may be so associated' as to make it advisable to merge the same, as shown at 28.

These bearers are useful for receiving the compressive strains at the edges of the plates, and in intermediate portions of the plate, which would otherwise be devoid of support in the plane of the printing surface,

When employing my improved device. Thesebearers are 'removed from the plate in the course of operation on the plate' preferably after employment vof my-'improved device thereon, the marginal bearers being re-y moved, as by sawing, and the interior bearers being removed, as by routing, the latter operation leaving spaces in the faceof the plate free of vprinting function. My improved device is, however, employable on plates Whichare not provided With bearers.

I have in Fig. 1 shown an exemplification of the printing face of a printing plate to be corrected, in this instance by compression, illustrating the differences in solidities of the printing portions of a printing plate, and its bearers. In this exemplification the partl 31 represents a solid portion, the parts 32 intermediate portions, and theparts 33 high-light or .light portions of the printing surface.

One of the characters -of printing plates upon. which my present invention is employable, is shown, described and claimed in Letters Patent No, 1,317,967, granted me October 14, 1919,' for method of curving printing plates and printing` plates curved thereby;

The printing plate may, before being coinperssed by my improved devicefhave its back or rear face shaved. Shaving of the back of the printing plate may be accomplished by any usual means, or, for instance, by a shaving -machine of the character of that shown, described and claimed in Letters Patent No. 1,282,013, granted me October 15, 1918, for method of and apparat-us for shaving printing-plates, it being assumed that such shaving machine having a flat bed and linearv shaving movement between the shaving elements and the printing plate be einployed, when operating on a flat plate, and that such shaving machine having a concavely curved bed and rotary shaving movement be employed when shaving a curved plate.

The printing plate 'in its original condition is of approximate uniform density throughout, this density of backing material being exemplified by the uniform spacing of the lines representing the cross-sectioning be a curved plate. The printing plate, when first formed, or when reduced to approximate uniform thickness throughout at its printing lines, by shaving 'its rear face, has,

@any soft or porous spots in' the printing plate, and press all portions of the printing surface of the printing plate toward a given surface, 1n order to locate all portions of the printingsurface in the projection of the same surface, that is, in the same plane if the plate be a flat plate andinto the same projection of a cylinder if the plate be a curved plate.

, The printing plate, especially the backing material thereof, is con'ipressed'by my improved device, preferably selectively' accortiing to the solidities of the printing portions of the printing plate. Thustheportions of the printing plate at the printing portions thereof `which are solid, are compressed to greater densities than those portions thereof which are provided. With high-lights or intermediate solidities of printing surface. These differences in densities are indicated in Fig. t by the differences in the closeness of the' cross-sectional lines. I accomplish the compressing operation preferablyiby placing the printing, plate,

' throughout the area of the same, and pref- When a fiat plate, with its printing face upon a plane hard surface, preferably of greater area than the area of the printing plate, as of a resistance member 40, which may be a steel slab, all portions of which surface are in the same projection of a given surface, and providing a compressing member, exemplified at 4.1, preferably of greater area than the area of the printing plate` which I apply to the backing surface of the printing plate, this compressing member being provided With hard contact faces acting upon thev backing of the printing plate in equidistant relations throughout from the hardened surface of the resistance member coactingjwith the printing surface of the printing plate. j

Pressure is applied to cause approach between said compressing member and the eoaeting resistance member, to compress the printing plate betiyeen said surfaces so as to causecempressioir of the printing plate, these hard contact faces preferably compressively acting upon the backing of the printing plate vvliich, n practice, is usually softer or more readilycompressible than the niateriai of the printing surface of the printing plate, which isvusually a printing shell. The printing surfaceis in any event supported by the plane hardened. surface of the resistance member to prevent crushing thereof or injurj thereto.

Protuberances and recesses are located at the back portion of the printing plate to aid in the compression of the printing plate. I prefer to employ a compressing member Whose compressing surface comprises such protuberances and recesses, and in Figs. 4, 5 and 6 shovs7 such a member having protuberances having spaces therebetween. These protuberanees or compressing areas are represented as elevations 43, between which there are depressions .44. These elevations preferably have sloping sides 45 forming the walls of the depressions, the sides sloping aWay from each other atthe respective elevations, for contractingv the depressions toward their bottoms preferably to appreciable extent, and the depres- .f-:ions are arranged to receive 'material of the backing due to the entrance into the backing of the elevations. The materially sloping sides of the depressions react upon the material'received in the depressions to cause compressing of those portions of the maferial of the backing received in said depressions. The sloping sides also afford relief for permitting ready removal of the -cornpre'ssing member after compression has taken place. preferably a hardened steel plate.

One of the objects of providing the raised compressing faces and coacting depressions is top'ermit the compressing faces to compressingly act on the backing material erably to enter the backing material for eX- erting the compression, the materially sloping walls reacting With compressive pressure upon the backing material received in the depressions, thereby enhancing the compressive elfect by employment of less pressures, and distributing the pressure throughout the printing plate, avoiding injury to the printing surface, and preventing spreading of the printing plate in the direction of the plane' of the plate, in order to maintain all printing lines of the lprinting surface in original relations in the directions of the plane of the plate to enable hair-line registry between printing plates of a set of plates, especially useful in so-called multicolor Work.

A` printing plate is in practice, during the printing operation, subjected to greater pressures per area at the Solid portions thereof, than it is at the other portions thereof, for instance, the high-light or light printing portions of the same. I therefore provide means whereby the backing of the printing plate at the solid portions thereof is caused to have greater density per area than .the backing portions of the prin-ting plate Iat, the other portions thereof, for instance the high-light portions.

The compressing member isl I 'compressing member provided with the compressing elevations and coacting depressions is placed upon the back of the printing plate, so as to coact with the backing material ofthe printing plate. A plunger 49 of thev press coacts with the bed thereof, its presser surface and bed surface being equi- 'ing the depressions 52 therein, and sloping distant from each other vof the pressure causes the throughout their areas, andthe movable element, namely, the plunger, being guided, as by guides 50, as is usual in a press of this character, in true right lines perpendicular to such surfaces when applying the pressure. The applying compression of the printing plate in manner hereinbe'fore described, and solidifies the same, including any soft or porous spots or portions therein.

I have shown the compressing elevations as having square areas. Other forms of compressing elevationsmay be employed, or the compressing elevations may be connected with each other for forming disconnected depressions between said elevations, for instance as shown in Figs. 11 and 12, in which the compressing elevations are by the continuous elevated portions 51 havwalls 45.

I further prefer to einploy compressing elevations of different areas and spacings according to the yaverage solidities of the printing surface of the printing plate to be compressed, and prefer that the greater the amount of solid areas there are in the printing plate, the greater shall be the proportion op' compressing elevations in the compressing ate. A p Thus, as examples, I have in Figs. 7 and 8 shown respectively a plan view and 'a cross-section of a portion of a compressing plate which I prefer to employ when operating upon printing plates having a large amount of solidsin their printing surfaces. 4Such plate may for instance have forty-live per cent of its area as elevation surface and fifty-five per cent of its area as depressions. The outer ends 46 of the elevationsmay be .tive thirty-seconds inch square and the sloping sides 45 have an inclination of sixty degrees.

In Figs. 4, 5 and 6, I have exemplified respectively ak cross-section anda plan view of a portion of a compressing member which I prefer to employ with a .printing plate exemplified' found desirable pressures having substantially balanced areas of solids and high-lights or intermediate conditions of solidities of printing surfaces, on which the area of compressing surface may amount to twenty-five per cent and the areas of` depression to seventy-five per cent of the total area of the compressing member; and the outer ends 46 of the elevations be one-eighth inch square, an inclination of sixty degrees. y

I have in Figs. 9 and 10 illustrated respectively a plan view and a cross-section of an exemplified portion of `a compressing member, which I prefer to employ for coacting with printing plates having a preponderance of high-lights, on which the areas of the compressing faces maybe twelve per cent and of the depressions between the same eighty-eight per cent of the entire area of the compressing member, and the outer ends 46 of the elevations be three thirty-seconds inch square, and the sloping sides' 45 have an inclination of sixty degrees.

.All of the said elevations may have a height of one-twentieth of an inch, and the bases of said sloping sides be spaced apart to provide the approximate areas mentioned. These examples are, however, exempliications and not limitations, as the areas, proportions of area and inclinations may vary within the spirit of my invention.

Further instancing desirable pressures to be employed in my improved device, and instancing a 'printing `plate comprisin an electro-deposited copper shell and a bac ring composed of a cast backing metal, such as hereinbefore described, comprising lead, tin and'antimony, it may be stated that I have for instance upon a printing plate having a substantially solid printing surface, and a size ten inches by twelve inches or one hundred and twenty squareinches, to bea range of from one hundred and sixty tons to-two hundred tons for the entire plate, equaling a range of from substantially one and one-third tons per square inch of printing plate to one and two-thirds tonsper square inch of printin plate; that when compresslng such printing plates of the given size having a medium solidity of printing surface, aggregate pressures having a range of from eighty tons to onehundred and sixty tons lpressure may be employed, representing pressures having a range of from two-thirds .of av tonper square inch to substantially and the sloping sides 45 have I hundred and fifty further, that in employing my improved method on printing plates in which the backing material is very hard, I have found' desirable pressures for instance upon a printing plate having a medium solidity of printing surface, aggregate pressures having a range of from one hundred and fty tons to three hundred and fifty tons pressure may be einployed, representing pressures having a range of` from one anda fourth tons per square inch to substantially three tons per square inch; and that When compressing such printing plates of such given size having a preponderance of high-lights, aggregate pressureshaving a range of from fifty to one hundred and fifty tons may be em ployed, representing a .range of from substantially one-half to one and a quarter tons per square inch of printing plate. The medians of the respective ranges of pressures have been'found suitable for the averages of said characters of plates. The pressures mentioned may vary according to the character of backing material and printing facev employed, and are given as instances and not as limitations.

I have found, in printing plates, especially such as comprise printing shells of electrodeposited metal, and also in plates other- `Wise formed, that the edges or boundaries, as at 54, of printing surfaces are in practice higher or more prominent in unprepared printing plates than the printing surfaces, as at 55, between suoli edges or boundaries. Exemplifying this condition, I have found that, for instance, the d ots in high-light areas, when subjected to highly magnified inspection, are really not dots, but are inclosing circles, the inner areas of which are sunken and either do not print or print very lightly, although to the naked eye they appear as fully developed dots.

By employment of my improved device, I am enabled to press the printing areas between boundary edges or lines into 4substantially the planes or projections of such print ing boundaries or lines, so as to minimize the difference between such areas and said boundary edges or lines in printing for enhancing the printing effect. By means oi my invention, I further bring all portions oi the printing surface into the same projec tion of the same surface so as to minimize the necessity for overlaying and underlaying and producing highly lefficient printing.

scope of the appended claims.

In subjecting the printing plate to the compressive actions hereinbefore described, I produce greater densities in the solid por tions of the printing plate than in the high light portions of the same. 'In the highlight portions of the printing plate there are greater areas in the printing face which ari. considerably depressed for avoiding print ing thereof, and While all parts of the area of the printing plate are subjected to the same pressure in the compressive action upon the same, portions are resisted by greater areas of conr tact between the printing surface. and tlu-J coacting resistance plate, u on which the same rests, than at the highlight portions of the printing plate, Where greater imprinting areas are located.

These unprinting areas permit a portion of the metal being compressed to find relief in such imprinting areas, `for causing less densities in the metal of the backing of the plate at those portions of the printing plate having more openareas in their printing surface than the solid portions thereof, this relief of density varying according to the solidities of the printing portions, the high' light portions being provided With the least densities. Forming the Walls of the depressionsofthe compressing plate materially sloping in the manner hereinbefore described aids materially in accomplishing these results.

The relief of density mentioned is received in the imprinting depressions, which are in practice increased in depth, Where necessary` as by routing or/otherwise, in finishing the plate, but the distance of perpendicular yield of the bottom of these depressions toward the printing surface is slight. The

distance of reception of the compressing faces into the plate may be instanced as one tenth the thickness of the plate, although this distance may vary Without departing from the spirit of my invention Within the The compressive action upon the plates in my inr proved device is preferably greater than any compressive action on said plate by any pres sures to which the printing plate is subjected in the printing operation, to avoid compression of the printing plate during printing.

Vhen printing from a plate made accord-- ing to my improved device, therefore, those portions of the plate which are siibjegted to the greatest pressures per area in the print ,ing operations are resisted by the greater the pressures at the solid c lill) densities in the printing plate, While those i portions of the printing plate which `are subjected to the less ,pressures per area in the printing operation, for instance, the high-light portion of the printing plate, are

resisted by the1 portions of the printing plate y of less density, providing resistances in the printing plate proportional to thev printing l i i A printing of the pressures per area required -for proper pressed, the backing surface thereof will' have the form of the compressing face of the compressing member impressed therein, for instance forming ridges 57, as shown in Figs. 4 and 13. I therefore bring the printing plate to uniform thickness at its printing portions by removing the ridges in the backing surface thereof, for instance, by e1nployment of a shaving machine, as hereinbefore mentioned, to take a shaving or shavings off of the backing of the same, to remove the undesirable ridges therein, andreduce the. printing plate to uniform thicknesses at its printing portions.

he compressing member may if desired be arranged in curved form and means provided whereby the printing plate in curved form may be compressed. y

Thus I have in Figs. 14 tor20, inclusive, illustrated an exemplifying machine by means of which ing plates may be obtained. Y

In this-exemplification, there is a bed 61,

which has a supporting face 62. and serves as the resistance member for the printing plate, preferably of greater area than the area of the printing plate. and harder'tha'n the printing face with which it is to coact,

and preferably formed on the sector of a cylinder having the diameter of the path of the printing surface of the printing plate while printing. The curved printing plate, represented at 24, is laid on this curvedsurface, with its printingface toward said sur-` face. Pressure is applied for causing the printing surface to intimately contact thisI r curved surface so as to locate the printing surface in the projection of the sector of its proper cylinder. Y

The backing of the cylinder is then compressed, preferably on lines substantially perpendicular to the printing surface, or by pressures directed radially of said surface,

and prefera ly in manner to maintain the distance relations, in the projection of the printing surface, l of said surface, in order to maintain theregistry function of the printing plate. I have exemplified this as accomplished by means' of compressing faces having compressing elevations-66, havingnsloping sides 45, and depressions 67, similar to theelevations 43 and depressions 44 of the compressing memthis case, the com.

ber 41, except that in' pressing member, represented generally at 68, is arranged on the sectors 'of a cylinder for coacting with the curved surface at the printing plate.- The sides 45 slope materially for substantially contracting the depressions toward their bottoms, whereby said sloping sides of various printing portions of' compression of curved-printvof the between the printing linesv vided with providing eccentrics the depressions react upon the material received in the depressions to cause compressing of those lportions of the material of the backing thus received in said depres sions, as explained with reference 'to the compressing faces and sloping wallsl employed in compressing flat plates.

I haveshown these compressing elevations arranged on compressing plates 70, suitably secured' tocompressing bodies 71, as by a tongue andgroove joint 72 between the same. or the compressing plate and its body may be vformed as an integral structure. The compressing plates are preferably hardened steel plates. The respective compressing sectors of the compressing member 68, which are arranged to be moved radially with relation to the curved-printing plate.` In arranging the compressing faces with relation to. the sectors ofl the compressing member, I prefer that thedepressions between ele'- vations be coincident with the lines of separation between the sectors.

n exemplication of means for causing the compressing 4m'oveme'nt may comprise a ram 75, moved in a guide 76, in a frame 77 machine, and having wedge faces 78 thereon, arranged as sectors of frusto-cones, which coact" with-complemental wedge faces 79 on the sectors o f the compressing member. Any suitable means may be provided for operating the ram. I have shown the same as provided with a screw 80, with which a nut 81 is threaded, the nut being shown as in the hub of a gear 82. The nut is prevented from moving endwise but is permit-f ted to rotate.

A' pinion 83 meshes with the gear. The pinion is on a shaft 84 journaled in bearings 85 on the frame, and having a hand-wheel 86 thereon for operating the same.

The `sectors of the compressing member are provided with radially arranged guides 87, which are guided in guideways 88, in aprons 89, 90, of the machine frame, the sectors being guided in similar'paths at their respective ends. The sectors -may at that end thereoftoward wh'ich the ram moves be provided with extensions 91 and additional guides -92 slidable in guideways 93. The re# spective sectors are at each end thereof proa lug 94, a spring 95 between said lug, and a ledge 96 on the apron, normally urging the sector ltowarditsoperating part and normally urging separation between the compressing member and the curved plate, y

Means are provided for. ready reception of the plate between the bed .or resistance member and the compressing member, which is exemplified as accomplished by raising -plates and their respective bodies compose luc and lowering the bed, as 'by means of guiding the bed in guides 98 in the' frame, and 99, fixed to shafts 100, journaled in bearings `101 of the frame, two

j Within the spirit of pressing member printing surface,

of these shafts being shown. The eccentrics act on contact faces 97 on the bed. Arms 102 are fixed to the shafts. A link 103, articulated at 104C with the-arms, connect thearms for combined movements. One of y these arms may be extended as a handle 105.

Movement of the bed toward the comis preferably limited by stops 106 to locate the curved f ace of the bed at such point, so that it lies in the sector of the cylinder on which the plate has been curved, or which is coincident with the cylindrical path of the printing plate during the printing operation, and to locate this sector at such distance from the frustocones of the ram, s that the axes of these frusto-conesand said sector will be coincident. This movement also preferably causes intimate contact between the rear face of the backing of the printing plate and the compressing member to arrange the printing plate on its true curvature. I The radial movements ofthe sectors of the 'compressing member are substantially perpendicular tothe various portions of the printing plate with which said sectors coact,

Lis the same plane,

the compressing face of said sectors being of such construction as to maintain the printing plate as .a whole to its original dimensions and to maintain the distance relations, in the projection of the printing surface, of the printing lines of said snrfacm hereinbefore explained withy relation to the compression filat plates.

The action and results of compression and solidiiication of the curved plate are the same as heretofore explained in connection with the compression of fiat platesfrThe portions of the curved printing plate comprising solid printing areas are compressed to greater density than the portions of the plate at which lighter printing surfaces are located. Compressing faces having various shapes andareas may also be employed in compressingcurved plates, as explained in relation to compressingdat plates. It is obvious, of course, that other means Vmay be employed for causing approach and recession between the curved printing plate and the compressing member or for causing compressi-on of the curved printing plate, my invention and the scope of the appended claims. y

The rear face or backing of the curved printing plate has the ribs or projections, due to compression, removed, as by shaving, for instance, by employment of the shaving machine hereinbefore referred to.

The marginal bearers 25 are also preferably trimmed from the plate, -Whether fiat or curved, for instance. in the line of the grooves 26 between said bearers.V and the and the edge of the plate provided with a suitable attaching face for ing from a securing the plate to the plate cylinder or to a supporting block by any ordinary or Wellknown means.

' If the printing plate be provided with' portions which must be removed from the printing side prior to printing the plate, for instance, interior bearers, such removal is accomplished, as by routing. .The printing plate may, if desired, be subjected to additional reinements, provings and corrections, as explained in my aforesaid pending application, of which this 4is a division, but my improved device may be employed without such steps and refinements, and produce a highly improved printing plate.

The printing plate, whether fiat or curved, may be instanced to be three-sixteenths of an inch thick in its finished state, but the diameters and dimensions given are merely exempliiications, and may be altered` or changed, or othel` diameters and dimensions substituted, ,within the spirit of my inven- 4tion'and the scope of the appended claims.

By means ofiny improved device a printing plate is obtained having a printing surface. the printing lines of which are located in the projection of the same surface, that and the same surface of a cylinder or sector of a cylinder if the plate be a curved plate, as determined by print pressures. In printprinting plate operated on by my improved device, the tympan surface upon 'which the sheets of paper or other material being printed are laid in the printing operation, may also be in the projection of agiven surface, Aeither comparatively hard, so that the printing contact between the paper being printed and the printing plate compressed by my improved device, is what may be termed a kiss contact between the papery and the ink for transferring the pigments of ink to the paper, and all rubbing contact between the paper and the ink whichis incident to causing the paper to be received in depressions or causing the paper to be bent over bulges in the faces of make-readies as now generally employed, 'may be avoided.

Having thus fully' described my invention, what I claim 'as new, and desire to secure by Letters Patent, is z.

l. In compressing means for printing plates having different preponderances of solidities of printing portions in their printing surfaces, said compressing means having elevations and depressions having different areas in accordance with said different preponderances of solidities of printing,r portions in said printing surfaces.

2. In compressing means for printing plates respectively having di-ifeiences of solidities of printing ortions in their printing surfaces` the com ination of a resistance member, and coacting compressing members if it be a straight plate,

plane or cylindrical, and be respectively having elevations and depressions having different' areas in accordance with the respective differences of solidities of Asaid printing portions in said printing surfaces.

3. In compressing means for printing plates having different preponderances of solidities of printingportions in thei'r printing surfaces, the'combination of a supporting member, coacting compressing members, said printing plates, the latter arranged to be received between said supporting member and said coacting compressing members, said last-named members and said printing plates having a surface between them provided with elevations and depressions having different areas in accordance with said different preponderances of solidities of printing portions in said printing surfaces, and means causing approach `between said compressing members and said supporting member for compressing said printing plates.

In compressing means yfor compressing printing plates respectively having differences of solidities of printing portions in their printing-surfaces, the combination of a supporting member, coacting compressing members respectively having elevations and depressions having different areas determined by therespective differencesof solidities of printing portions in said printing surfaces, and means for causing approach between said members.

5. In compressing means for compressing printing plates respectively having differences of solidities of printing portions in their printing surfaces, the combination of a supporting member, coacting compressing members respectively having elevations and depressions having different areas determined by the respective differences of solidities of printing portions in said printing surfaces, means for causing approach between said members. and resilient means causing separation between said members.

6. In compressing means for compressing curved printing plates having different preponderances of solidities of printing portions in their curved printing surfaces, the combination of a plurality of compressing means respectively having curved compressing surfaces provided with elevations and depressions having different areas in accordance with said different preponderances of solidities of printing portlons in said curved printing surfaces.

In compressing means for compressing curved printing plates respectively having deerences of solidities of printing portions in their curved printing surfaces, the combination of a curved resistance member and coacti'ng curved compressing members respeccompressing tively having elevations and depressions having different areas in accordance with the `members respectively respective differences of solidities of said printing portions in said curved printing surfaces.

8. In compressing means for curved printing plates respectively having different preponderances of solidities of printing portions in their curved printing surfaces, the combination of a plurality of curved compressing parts respectively divided into sectors, said respective curved compressing parts having curved compressing surfaces having elevations and depressions having different areas in accordance with the different preponderances of solidities of printing portions in. said respective curved printing surfaces.

9. In means for compressing curved printing plates having differences in printing effects of different printing portions in their printing surfaces, the combination of a supporting member, and coacting compressing members respectively having elevations and depressions determined by the respective-,differences in printing effects of said different printing portions. i

10. In compressing means for compress- 'ing curved printing plates having differences in the printing effects of different printing portions in their printing surfaces, the combination of a supporting member, and coacting compressing members respectively having kelevations and depressions having different areas determined by the respective differences in said printing effects.

11. In compressing means for compressing curved printing plates having diii'erences in printing effects in different printing portions of their printing surfaces, the combination of a supporting member having a supporting face arranged on the sector of a cylinder, and coacting compressing having" compressing faces which vary in accordance with the differences in printing effects of said different printing portions, said compressing faces arranged as sectors of cylinders substantially concentric with said first-named sector.

12. A compressing means for a curved printing plate comprising a compressing member including a plurality of compressing parts having curved compressing faces and means causing relative compressing movement between said compressing parts. A13. A compressing means for a curved printing plate comprising al resistance member having a curved resistance face arranged thereon, a compressing member having a curved compressing face coacting with said curved resistance face, and forming a pair of members, a member of said pair of inembers arranged in sectors, and means for moving said` sectors toward the other of said members.,

rae l opposed inner and outer members between which said curved printing plate is arranged to be received, there being a surface provided with indentations and depressions between the body portions of said inner member and said printing plate, said inner member comprising a plurality 0f parts, and means for causing approach of the parts of said inner member toward said outer member by substantially radial forces.

16. Inmeans for compressing a curved printing plate having an outer printing surface, the combination of a curved support vfor said outer printingsurface, and a compressing member comprising a4 plurality of parts arranged to act upon the inner surface of said curved printing plate in a plurality of directions.

17. In means for compressing a curved printing plate having an outer printing surface, the combination of a curved support for said curved printing surface, an inner member comprising sectors having'faces provided with elevations and depressions coaeting with the inner backingI portion of said curved printing plate, and means for causing the movement of said sectors toward said curved support in substantially radial lines.

18. In means for correcting a curved printing plate having an outer printing surface, the combination of substantially concentric surfaces between which said curved printing plate is arranged to be received, and means for causing approach .between said surfaces in a plurality of substantially radial paths. f

19. In means for correcting a curved printing plate having an outer printing surface, the combination lof curved surfaces Ibetween which said curved printing plate is arranged to be received, and means for causing approach between said curved surfaces in a. plurality of directions, there being elevations and depressions at the inner one of said surfaces, and the said elevations arranged to be pressed into said backing by said approach between said surfaces.

20. In means for -correcting a curved printing plate having an outer printing surface, the combination of curved surfaces.

` contracting toward their bottoms in manner to react with. pressure upon the 'printing plate during compressing of said plate.

21. In compressing means for printing plates, the combination of a curved resistance member, a curved compressingr niember, a printing plate arranged to be received between said curved members, said curved compressing member and said printing platel having coacting surfaces including elevations and depressions, and means for causing approach between said members comprising compressing sectors.

22. In compressing means for printing plates, the combination'of a curved resistance member and a curved compressing member, the printing plate arranged to be received between means -for causing approach between said members comprising compressing sectors, means for moving said sectors in substantially radial lines, and resilient means for retracting said sectors.

v 23. In compressing means for compressing curved printing plates, the combination 'of a resistance-member having a curved resistance surface for the rintino late a curved compressing member comprising sectors, means for causing movement of said resistance member toward said compressing member, and means causingmovement of said sectors toward said resistance member.

24. In compressing means for compressing curved printing plates, the combination of a resistance member having a curved resistance face for the printing plate, a compressing member comprising sectors, means for guiding said sectors in radial lines, and operating means for'said sectors, said operating means and said sectors comprising coinplemental wedge faces.

25. In compressing means for compressing curved printing plates,the combination said curved members,`

of a resistance member having a curved resistance face for a printing plate, a compressing member comprising sectors, means 'for guiding said sectors 'in radial lines, a

ram, said ram and said sectors' provided with complemental moving faces, and means for moving said ram lengthwise of said sectors.

26.` In compressing means for compressing curved printing plates, the combination of aresistance member having a curved resistance face for a printing plate, a cominziens@ pressing member comprising sectors, means for guiding said sectors in radial lines, a ram, said ram and said sectors provided with complemental moving faces, means for moving said ram lengthwise of said sectors, and resilient means for retracting said sectors. 1

27. In compressing means for compressA ing curved printing plates,the combination of a resistance member having a curved face for the curved printing surface of the .printing plate, a compressing member comprising sectors, means for moving said resistance member toward and from said compressing member, a ram at the inner ends of said sectors, said ram and said' sectors comprising means for resiliently retracting said sectors along said guides, and means for moving said resistance member toward and from said compressing member.

29. A compressing member for compressing a curved printing plate comprising sectors having elevations and depressions ar ranged substantially on the sector of a cylinder and having sloping walls between them to form said depressions contracting toward their bottoms in manner to react wlth pressure upon the inner wall of -the curved printing plate during compressing of said curved printing plate, and means for moving said sectors in different radial paths.

30. A curved compressing member for compressing a curved printing plate comprising elevationsand depressions arranged substantially on the sector of a cylinder, said elevations arranged to enter the inner face of the curved prmting plate, and means for causing movement of different portions of said compressing member in different paths.

In testimony whereof, I have hereunto signed my name' in the presence oi. two subscribing witnesses. LESLE W. CLAYBOURN.

Witnesses:

JOSEPHV LEWKUHL, DEIMA WnRNsIns. 

